Stage-specific modeling of the insecticidal impact of heat and cold on the saw-toothed grain beetle, Oryzaephilus surinamensis

The saw-toothed grain beetle, Oryzaephilus surinamensis , is a significant pest of stored products worldwide, with increasing resistance to chemical insecticides necessitating alternative control methods. Temperature-based treatments offer a promising non-chemical approach to pest management, yet comprehensive evaluations across all life stages remain limited. This study assesses the insecticidal efficacy of extreme temperature treatments—both heat and cold—on O. surinamensis , including the previously uninvestigated pupal stage. Laboratory experiments determined mortality rates across various temperature-time combinations, with exposure durations of 1, 3, 6, 9, and 24 h. The tested temperatures ranged from 5 to −15 °C for cold treatments and 30–55 °C for heat treatments. Results indicate that eggs are the most susceptible to both heat and cold treatments, while larvae exhibit the highest tolerance. Complete mortality was achieved under optimized conditions, with heat treatments acting more rapidly, whereas cold treatments offered an energy-efficient alternative. Statistical modeling was applied to predict treatment effectiveness, providing valuable insights into optimizing temperature-based pest control strategies. The findings of this study highlight the potential of extreme temperature treatments as a sustainable and effective method for managing O. surinamensis infestations. By offering a viable alternative to chemical insecticides, temperature treatments can enhance pest management strategies in food storage and processing industries. The predictive models developed here contribute to improved implementation of these techniques, supporting long-term, environmentally friendly solutions for stored-product protection. • Eggs showed highest mortality under both heat and cold treatments. • Larvae required longest exposure and highest temperatures for control. • Complete mortality achieved at −10 °C (24h) and 50 °C (12–24h). • Predictive models accurately estimated mortality across life stages. • Heat and cold treatments offer effective, chemical-free pest control.